Laptop vs. Bathtub

[Mr Happy]

Laptops get completely destroyed if you immerse them in water, including the loss of all information on the disk. This makes for an expensive and very annoying disaster. Quite apart from any slight risk of injury to the person, it is a really good idea to keep laptops far away from water.

 

[StarHalo]

Laptops get completely destroyed if you immerse them in water, including the loss of all information on the disk.

You'd kill the hard drive but all the info would still be there; the drive casing is airtight, so the hardware within it would be fine. A data recovery service could get the data off the platters and ghost it onto a new drive, but it's a process that usually costs more than a new laptop..

The consensus seems to be that a laptop in an occupied bathtub wouldn't harm the occupant, but what if the person immediately grabbed the PC while it was in the water, to pull it out quickly?

 

[Lawliet]

You'd kill the hard drive but all the info would still be there; the drive casing is airtight,

THey have a hole for pressure compensation. The dust filters might keep the water out for a while, but I wouldn't want to depend on that.

but what if the person immediately grabbed the PC while it was in the water, to pull it out quickly?

Depending on the quality of the adapter either nothing happens, or you get zapped by about half the line voltage. Thanks to the high inner resistance its only somewhat painful, but if it surprises you...
The latter shouldn't happen, but some of the AC adapters do it anyways. :shakehead

 

[etc]

Make sure she runs the laptop on battery. If she runs it on mains and the charger PSU brick gets pulled into the bath that could be game over...

Movies take so much energy that you won't even get 2 hours on one 9-cell pack. You have to plug it into the main power.

 

[StarHalo]

Movies take so much energy that you won't even get 2 hours on one 9-cell pack. You have to plug it into the main power.

My 11.6" ultralight can do a 2 hour movie, her 15.6" monster cannot.

And our bathroom mains is a GFCI, plus the circuit breaker has redundancy.

 

[ama230]

I had just wanted to post to all those who have not and do not know anything about electrical potential. Also quit googling your information and then claiming it as if you are an electrical engineer or an expert of some sort.

It takes lower voltage and a usual result of voltage current to kill you in DC than it does AC. This is a fact as I know from first hand experience(Am a power engineer/electrical engineer) with these claims and am no amateur.

Then to break it down for those (lawliet and mr happy)

Water:________Volume_________ Pressure ___________Path of channeling(Restriction of flow)_____________
________________=_____________=______________________ =_________________________________
Electricity:_____Voltage ________Current_______________Resistance___________________________________

Also:
AC = Alternating current = DEADLY

DC = DIRECT CURRENT = EXTREMELY DEADLY

Then if DC or AC voltage doesn't matter then try tazering yourself in a bath tub and see what happens as 1kv to 100kv DC is all the same and will paralyze you thus killing you in a body of water. Also if you have been had by a leg of 220 or 430 then you would know that there is always going to be a substantial amount of current to flow along with it as its a fact of physics and nature. Momentum or current are what definitely kill you but its the weight/mass or voltage that is also doing the damage.

The rest of the factors are given constants as they have been somewhat right for a while and with a little tolerance of course with anything.

There is no weird resistance of a tube, if the body of water has a lower resistance its going to go across you faster than across the tube. Electricity acts a lot like water and air and will travel the least path of resistance. We are not trying to get a voltage out of a tube as a CFL bulb does not act as a energy storage device it only transfers and converts it.

Also there is no direct path in the body as it goes in all directions as we are made up of majority of water. It goes across the brain toes and heart all the same as its being equally distributed unless you get tons of iron in your blood and it only goes through you circulatory system...

Think twice before you make yourselves look stupid (lawliet, mr happy)

 

[StarHalo]

Think twice before you make yourselves look stupid (lawliet, mr happy)

No need to be confrontational. You seem to know the math involved, so what is your conclusion about a 19VDC appliance drawing 1.58A being dropped into a bathtub with someone in it?

 

[DM51]

ama230... Please edit your post immediately to remove the rude remarks you made about other members.

 

[Justin Case]

I had just wanted to post to all those who have not and do not know anything about electrical potential. Also quit googling your information and then claiming it as if you are an electrical engineer or an expert of some sort.

It takes lower voltage and a usual result of voltage current to kill you in DC than it does AC. This is a fact as I know from first hand experience(Am a power engineer/electrical engineer) with these claims and am no amateur.

Then to break it down for those (lawliet and mr happy)

Water:________Volume_________ Pressure ___________Path of channeling(Restriction of flow)_____________
________________=_____________=______________________ =_________________________________
Electricity:_____Voltage ________Current_______________Resistance___________________________________

Also:
AC = Alternating current = DEADLY

DC = DIRECT CURRENT = EXTREMELY DEADLY

Then if DC or AC voltage doesn't matter then try tazering yourself in a bath tub and see what happens as 1kv to 100kv DC is all the same and will paralyze you thus killing you in a body of water. Also if you have been had by a leg of 220 or 430 then you would know that there is always going to be a substantial amount of current to flow along with it as its a fact of physics and nature. Momentum or current are what definitely kill you but its the weight/mass or voltage that is also doing the damage.

The rest of the factors are given constants as they have been somewhat right for a while and with a little tolerance of course with anything.

There is no weird resistance of a tube, if the body of water has a lower resistance its going to go across you faster than across the tube. Electricity acts a lot like water and air and will travel the least path of resistance. We are not trying to get a voltage out of a tube as a CFL bulb does not act as a energy storage device it only transfers and converts it.

Also there is no direct path in the body as it goes in all directions as we are made up of majority of water. It goes across the brain toes and heart all the same as its being equally distributed unless you get tons of iron in your blood and it only goes through you circulatory system...

Think twice before you make yourselves look stupid (lawliet, mr happy)

Well I do know that in the water analogy for electricity, water volume is not the water analogy for electrical voltage. Also, water pressure is not the water analogy for electrical current.

Water pressure differential is the water analogy for electrical voltage. Water volume flow rate is the water analogy for electrical current.

You might want to correct these basic errors to avoid having other readers of this thread place you in the same category that you placed Lawliet and Mr Happy.

 

[Walterk]

FWIW: Tools for safe working in wet environments are typically 42 volt.

 

[dave w]

I had just wanted to post to all those who have not and do not know anything about electrical potential. Also quit googling your information and then claiming it as if you are an electrical engineer or an expert of some sort.

It takes lower voltage and a usual result of voltage current to kill you in DC than it does AC. This is a fact as I know from first hand experience(Am a power engineer/electrical engineer) with these claims and am no amateur.

Then to break it down for those (lawliet and mr happy)

Water:________Volume_________ Pressure ___________Path of channeling(Restriction of flow)_____________
________________=_____________=______________________ =_________________________________
Electricity:_____Voltage ________Current_______________Resistance___________________________________

Also:
AC = Alternating current = DEADLY

DC = DIRECT CURRENT = EXTREMELY DEADLY

Then if DC or AC voltage doesn't matter then try tazering yourself in a bath tub and see what happens as 1kv to 100kv DC is all the same and will paralyze you thus killing you in a body of water. Also if you have been had by a leg of 220 or 430 then you would know that there is always going to be a substantial amount of current to flow along with it as its a fact of physics and nature. Momentum or current are what definitely kill you but its the weight/mass or voltage that is also doing the damage.

The rest of the factors are given constants as they have been somewhat right for a while and with a little tolerance of course with anything.

There is no weird resistance of a tube, if the body of water has a lower resistance its going to go across you faster than across the tube. Electricity acts a lot like water and air and will travel the least path of resistance. We are not trying to get a voltage out of a tube as a CFL bulb does not act as a energy storage device it only transfers and converts it.

Also there is no direct path in the body as it goes in all directions as we are made up of majority of water. It goes across the brain toes and heart all the same as its being equally distributed unless you get tons of iron in your blood and it only goes through you circulatory system...

Think twice before you make yourselves look stupid (lawliet, mr happy)

I laughed so hard I had to get the Depends.
You are trying to be funny, aren't you?

 

[TXArsonCop]

I had just wanted to post to all those who have not and do not know anything about electrical potential. Also quit googling your information and then claiming it as if you are an electrical engineer or an expert of some sort.

- huge snippage of partially revelant info -

Think twice before you make yourselves look stupid (lawliet, mr happy)

Actually sir.., this firefighter with 25 years experience (don't make me include the whole resume') thinks that YOU should stop MISINFORMING folks with your 'book knowledge.' It does help to get out of the office and into the field occasionally...

I know for a fact (ie. I have witnessed with my own eyes) that you can toss a working (turned on and blowing) hair dryer into a filled (with water) bathtub and NOT blow a breaker or GFCI. The hair dryer will NOT short out spectacularly like hollywierd would like you to think but instead become a VERY ineffecient water heater and circulation pump. I also know for a fact that you can get into the water and not receive a shock because I was the volunteer to do it!

Why? Because many homes for many years now have not had their plumbing bonded/grounded to the house's electrical system. And in even more newer homes ALL of the plumbing is plastic and CAN'T be bonded/grounded so there is NO ground potential. Even moreso if the tub/sink is an insulative material.

Older homes with bonded plumbing, cast iron tubs and cast iron D/W/V piping have ground potential. Even when they started putting in tubs made of other materials the metal drain hardware completed the 'circuit' into the tub for a victim to come into contact or for dirty enough water to conduct a shock.

I will admit though that when I re-created the hair dryer demo at home for the wife I got a bit of a tickle due to the LARGE amount of softener salt in our water due to extreme hard water.

A training outfit, Public Agency Training Council uses that demo in their 'electrical fire' class.

I AM NOT ADVOCATING AND ADVISE AGAINST TOSSING ANY ELECTRICAL APPLIANCE IN ANY BODY OF WATER THAT YOU OR ANOTHER PERSON ARE OCCUPYING. SERIOUS BODILY INJURY OR DEATH MAY RESULT.

 

[StarHalo]

I know for a fact (ie. I have witnessed with my own eyes) that you can toss a working (turned on and blowing) hair dryer into a filled (with water) bathtub and NOT blow a breaker or GFCI.

Ah, a very good point; I think the only metal part of my tub is the faucet hardware. And a hairdryer uses far more electricity than a laptop, so if all you'd get is a non-grounded "tickle", then the laptop wouldn't present a hazard at all. So a major factor would be how grounded the tub is..

 

[jugornot]

I'm no engineer, but I have 33 years in the electrical trade and hold the position of Instrument Tech. This is something of a misnomer as I am the last person called before an engineer is brought in. I work in an industrial setting with hands on of voltages from 5vdc to 2300vac and occasionally 69Kvac. I would feel safe with a laptop in a bathtub except fsh (freaky stuff happens.) I was called to a friends house one time because they thought they had a bad light in the pool. Turns out the light was fine grounded and everything, but the pump was not properly grounded. One of the windings in the pump had grounded supplying ac to the pool. The freaky call? Every time someone touches a light they get shocked. Way back then the lights were not low voltage, but it wouldn't matter as anything grounded would cause the same problem. They were lucky imho. I've seen batteries blow up when shorted and other freaky stuff. Just get her a shower radio and tell her you don't like wrinkly women.

 

[Quension]

Older homes with bonded plumbing, cast iron tubs and cast iron D/W/V piping have ground potential. Even when they started putting in tubs made of other materials the metal drain hardware completed the 'circuit' into the tub for a victim to come into contact or for dirty enough water to conduct a shock.

I wondered when someone was going to get to this point. The danger scenario here isn't so much being in the tub while something with live AC potential lands in it, it's more about what you're doing with your other limbs while one is near that item. Grabbing the facet, metal sink, etc for leverage while you reach over and pull out the hairdryer is likely to give you a shock. Or if the sink is grounded and no part of the tub is, then holding on to the sink as you get out of the tub. Etc.

It's any path that results in you being a better conductor than the water.

Also, it's not just cast-iron D/W/V; copper supply pipes may be tied to ground as well.

 

[TXArsonCop]

I almost mentioned the supply but I was getting long-winded and I figured some might quit reading, I also tought some might infer it.

As an aside your copper supply lines can be prone to 'pinholes' due to electrolysis if not grounded properly or in contact with other coductors such as reinforcing bars in the slab or nails in metal lathe or nails in contact with your electrical.

Having and working with a dad that's a master plumber has been very enlightening in this area.

 

[DM51]

ama230... your post #46 was unnecessarily aggressive. It was also gratuitously rude to 2 members, which was why I instructed you to edit it and remove the offending passages.

You have failed to comply; please therefore take the next 3 days off, and use the time to make a comprehensive study of Rule 4. On your return, we will expect to see a noticeable improvement in your attitude.

 

[ktm032]

There is a transformer in the supply of the CFL and this is supplied by the batteries in the laptop. It doesnt matter if there is a breaker to trip if the laptop gets wet. The computer is still going to supply power to the transformer. Then this is when we get a high voltage and it being mentioned it takes only a little current or voltage to kill someone with heart problems.

1) The laptop is definately done for.

2) The person is going to get a slight paralysis, depends on how long the batteries last until they run out when shorting.

3) Wouldn't advise it.

Actually the volume of stored water acts like capacitance(capacitor) and the pressure being regulated or stepped up acts like a inductor.

Terrible analogies above and messed those up.:thinking:

 

[TXArsonCop]

Unless the drain piping is grounded to the electrical there is NO ground potential. The laptop will not survive because of the sensitive electronics but there is NO hazard without a ground!

 

[StarHalo]

Unless the drain piping is grounded to the electrical there is NO ground potential.

So now that that's established, what would be an expedient DIY way to find out if your tub is grounded?